Magnetic tape cartridges have been used to conveniently and efficiently store and handle magnetic recording media for tape drives. One type of tape cartridge consists of a substantially rectangular exterior cartridge housing and a single reel containing a magnetic tape positioned within the housing. The cartridge housing includes an upper housing section and a lower housing section which substantially enclose the magnetic tape, which includes a cartridge leader. The cartridge leader becomes exposed through an opening in the cartridge housing during insertion of the cartridge into the tape drive. The tape drive is then able to engage and retrieve the tape from the cartridge for recording and/or playback.
The reel includes a hub, one or more flanges and a plurality of teeth that are exposed through an access opening in the lower housing section. A drive clutch on the tape drive engages the teeth in order to rotate the reel. Typically, a spring within the cartridge housing biases the reel toward the lower housing section. During engagement between the drive clutch and the teeth, the tape drive exerts a force against the reel, urging the reel toward the upper housing section, thereby partially compressing the spring to promote a secure engagement between the drive clutch and the reel. The tape drive then rotates the reel and guides the tape across a data transducer that reads data from and/or writes data to the tape. Although the reel can move generally longitudinally along the rotational axis, the reel can also move somewhat axially relative to the lower and upper housing sections to allow for drive tolerances.
While movement of reel between upper housing section and lower housing section is necessary during normal operation in a tape drive, it has been found that such movement presents problems during handling outside the tape drive. In particular, undesired movement of reel may damage the magnetic tape which is wound thereon. For example, if the cartridge is dropped or otherwise severely jostled, axial or tilting movement of reel may result in contact between the one or more flanges and the cartridge housing, which can cause contact between one or more flanges of the reel and the tape. In general the flanges can be relatively thin and can deflect somewhat easily. Because the current design preference among tape manufacturers is to develop tape that is thinner to increase storage capacity, such tape is also more easily damaged. Besides damage at the outside edge of the tape, winding phenomena which results in the uneven or staggered wrap (i.e. packslip, popped strand) of the tape onto the reel, also renders the tape vulnerable to damage. For example, damage to the magnetic tape may result in incorrect data reading and/or writing, or lost data by the tape drive.
Accordingly, the need exists to provide a cartridge that inhibits damage to the tape due to axial movement of the reel within the cartridge housing. Further, the need exists to provide a cost-effective, efficient method of manufacturing a media cartridge that promotes increased accuracy in reading and writing by the tape drive.